Surface covering



March 20, 1962 B. PALATlNl 3,025,772

SURFACE COVERING Filed June 20,. 1956 Fig. 1

United States Patent 3,025,772 SURFACE COVERING Benno Palatini, Blumenbergplatz 7, Sankt Gallen, Switzerland Filed June 20, 1956, Ser. No. 592,566 Claims priority, application Switzerland Feb. 21, 1956 3 Claims. (Cl. 94-4) The present invention relates to a surface covering adapted for use in landing fields, streets, floors, walls and the like.

It is already known for preventing cracks in coverings of large dimensions and in order to increase the resistance thereof, to provide the covering with a grid-like insert the interstices between the grid walls thereof being filled with an appropriate building material constituting the uppermost surface.

A prime object of the present invention is to provide a surface covering of this type in which the structure is made of a flexible material and in which the separate grid walls are at least twin-walled and closed at their upper end so that between the rigid cells of building material completely filling the grid openings there are formed compressible passages imparting in cooperation with the flexible structure to the whole surface covering a flexibility permitting adaption of the latter to inequalities of the subsoil.

This arrangement imparts to the surface covering a great flexibility permitting its intimate adaption to inequalities of the subsoil and also permitting its following of slight movements of the subsoil.

Other objects and advantages reside in the particular structures of the several forms of the invention, the structure of the several elements forming the same combination and relation of such elements, all of which will be readily understood by those skilled in the art upon reference to the attached drawing in connection with the following specification, wherein the invention is shown, described and claimed.

In the drawing:

FIG. 1 is a perspective view partially in section of a completed surface covering according to the invention,

FIG. 2 shows, also in perspective view, a grid element used in this surface covering,

FIG. 3 is a section taken along line III-III of FIG. 2 through the grid element shown in this figure and through an adjacent grid element, and

FIGURE 4 is a perspective view of the element of FIGURE 2 taken from the diagonally opposite corner of the element.

In FIG. 1 the subsoil to be provided with a surface covering is designated by 1. Preferably this subsoil is made airand watertight by an appropriate process previous to its provision with the covering hereafter described. A grid-like structure generally indicated by reference numeral 2 is then laid on to the subsoil 1. This structure 2 is formed of a plurality of square grid elements one of which is illustrated in FIG. 2. Into the free spaces or cells formed between the grid walls there is brought an appropriate structural material, preferably concrete, which is adapted to produce an uppermost covering fulfilling any required conditions. This structural material completely fills these spaces without any joints and is divided by the grid walls into a plurality of separate cells 3 of building material. Owing to the small dimensions of each concrete cell, formation of cracks is practically excluded. Each grid wall ofthe structure is twin-walled and closed at its upper end so as to form, as clearly visible from FIG. 1 and 3, in crosssection a U turned head-down. As the open side of each of these Us lies on the airand watertight subsoil 1 conduits or passages 4 are produced between the twin- "ice walls of each grid wall, which passages communicate all with each other. In order to produce surface coverings of large dimension in the described manner several elements identical to the one illustrated in FIG. 2 are connected to each other as visible from FIGS. 1 and 3. In order not to interrupt the intercommunication of the passages 4 between adjacent elements and further to prevent entering of air from the atmosphere into these passages 4 at the junction of two elements the edges of each of the elements are constructed in such a manner that lobes 5 of one element engage into the near-by cells of the adjacent element so that also between two adjacent elements there are formed passages 4 which are hermetically sealed from the atmosphere thus permitting heating of the covering by a heated medium as hereafter described.

At two sides of each element the grid walls are staggered with respect to the marginal edges as shown at 6, in that the height of the overlapped portions is about the thickness of material less than the height of the other parts. It results from this arrangement that even if several elements are connected to each other the upper edges of all elements lie in one plane which at the same time constitutes the surface of the covering (FIG. 1). In order to permit additional expansion the lobes 5 may be somewhat broader than shown.

The grid-like elements may be made from any appropriate flexible material. Preferably use may be made of synthetic materials such as for example nylon or any other polyamid.

Owing to the twin-walled arrangement of the grid walls with air cushioning in between the Whole described surface covering has a great flexibility permitting its intimate adaption to unevenness and rugged inequalities of the subsoil. At the same time the division of the covering material into a plurality of small-dimensioned cells permits use of a structure material which is substantially harder than the subsoil so that the present invention renders possible to provide a subsoil with a very hard and resistent surface covering in which no cracks occur upon changes in the configuration of the subsoil owing to the fact that the tensile and compression strains are taken up by the great number of small-dimensioned cells 3 and even more by the structure 2 itself.

As visible from the drawing the arrangement of the structure 2 is such that all passages 4 communicate with each other. This permits heating of the surface covering in a very simple manner by feeding a heating medium for example hot air or steam through the passages 4 hermetically sealed against the atmosphere. Preferably hot air will be fed at one end of the covering into all passages 4 extending parallelly to each other in one direction and for this purpose these may be made with a larger crosssection than the passages 4 extending transversely thereto. Of course it is also possible to insert heating wires into the grid elements as is shown at 7 in FIG. 3 and in this case the surface covering may be heated electrically. This last-mentioned method has the advantage that the heating zone is brought into immediate vincinity of the surface and simultaneously treatment of the subsoil in order to render it air-tight may be dispensed with. The advantages which result from the possibility of heating this covering for example the surface of landing fields for aircrafts, of streets and the like certainly need not be particularly mentioned here.

The possibilities of use of the surface covering according to the present invention are various. Besides the already mentioned use in landing fields for aircrafts it may be used for highways, streets, sidewalks, garage floors and even for floors in apartments and the like.

Instead of being heated the surface covering could of course also be cooled and then it may be used in coldstorage or refrigerating plants.

Instead of being twin-walled the walls of the grid elements enclosing the cells may also havea greater number of partitions.

Of course the surface covering according to the invention may also be brought onto already existing surface coverings for example onto concrete plates and the like.

Consequently, while I have shown and described what are now thought to be preferred forms of the invention, it is to be understood that the same is susceptible of other formsand expressions. Consequently I do not limit myself to theprecise structures shown and described hereinabove, except. as hereinafter claimed.

I claim:

1. In a surface covering for landing fields, streets, floors, and the like including a plurality of grid elements defining cellular, openings and building material filling the openings, the improvement comprising the provision of interlocking, grid elements each comprising a flexible rectangular grid of intersecting and interconnected grid members including inner members and peripheral members bounding the four edges of the element, saidmembers each having. spaced flexible side walls and a top wall, allof saidmembers being of the same height with the exception of the peripheral members bounding two contiguous edges of the element, said contiguous peripheral membersbeing of a height less than that of the other of said members by a distance equal approximately to the thickness of said top wall, the other two peripheral members each being of inverted U-shape and having inner dimensionsat leastequal substantially to the outer dimensions of said contiguous peripheral members, the outer side, wall of each of saidother twoperipheral members being notched at spaced locations corresponding to the spacing betweenthe inner grid members intersecting said contiguous; peripheral members, said notches being of a width at least equal substantially to the outer dimensions of the inner grid members and defining therebetween lobes of a width not substantially greater than the Width of: the cellular openings defined along said contiguous peripheral members, adjacent ones of said-grid elements beinginterconnected-With one of said other peripheral members of one element overlying one of said contiguous peripheral members of the other element and with the said lobes on the respective other peripheral members of the oneelement-interfitting in the cellular openings along the respectivecontiguous peripheral members of the other element.

2. In a surface covering for landing fields, streets, floors, walls and the like including a plurality of grid elements defining cellular openings'and building material filling the openings, the improvement comprising the provision of interlocking grid elements each comprising a square flexible grid of evenly spaced intersecting grid members integrally formed of aflexible material, said grid members defining therebetween a plurality of square cellular openings of uniform size and including inner members and peripheral members bounding the four edges of the element, said gridmembers each having spaced flexible side walls and a top wall and defining interconnected passages all of which communicate with one another, all of said grid members being of the'same height with the exception of the peripheral members bounding two contiguous edges of said grid element, said contiguous peripheral members being of a height less than that of the other of said gridmembers by a distance equal approximately to the thickness of said top wall, the other two peripheral members of each element being of inverted U-shape and havinginner dimensions at least equal approximately to the outer dimensions of said contiguous peripheral members, the outer side wall of each of said other peripheral members being notched at spaced locations corresponding to and aligned with the grid members intersecting the same, said notches being of a width equal approximately to the outer dimensions of the inner grid members and defining therebetween lobes of a. width equal approximately to the width of said cellular openings, adjacent ones of said grid elements being interconnected with one of said other peripheral members of one element overlying one of said contiguous peripheral membersof the other element and with the said lobes on the respective other peripheral member of the one element interfitting in the cellular openings along the respective contiguous peripheral member of the other element, the outer side wall of each of said contiguous peripheral members also being notched in the area thereof aligned with the inner grid membersintersecting the same for establishing direct axial communication between the passages defined by the last-mentioned grid members of the respective grid element and the passages defined by the aligned grid members of the grid elements connected.

therewith.

3. A grid element for the surface covering of landing fields, streets, floors, walls and the like comprising an integral flexible gridof intersecting grid members defining cellular openings-therebetween. and including inner grid members and peripheral members bounding the edges of the grid, said grid members each having spaced side walls,

and a top Wall, all of the grid members being of the same height with the exception of the peripheral members.

bounding some of the edges of the grid, the last-named peripheral members being shorter than the other grid members by a distance equal approximately to the thickness of said top wall, the other peripheral members being of inverted U-shape and having inner dimensions equal approximately to the outer dimensions of said shorter peripheral members, the outer side wall of each of said other peripheral members being notched at spaced locations corresponding to the spacing between the inner grid members intersecting said shorter peripheral members, said notches being of a width at least equal substantially to the outer dimensions of the inner grid members intersecting said shorter peripheral members and defining therebetween lobes of a width not substantially greater than the width of the cellular openings defined along said shorter peripheral'members, whereby two of said grid elements may beinterlocked by entering one of said Shorter peripheral members of one element into one of said other peripheral members of the other element with the, said lobes of the latter peripheral member entering into the cellular openings defined along the said one shorter peripheral member of said one element.

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